Urine potassium (K), Quantitative 24 urine or Random sample
- Collect 24 hours of urine.
- Procedure to collect 24-hour urine: Discard the first sample and note the time.
- Collect the rest of the urine for 24 hours and urinate the last sample into the container.
- Refrigerate the urine during collection.
- This study is done in renal and adrenal disorders.
- This is done for water and acid-base balance.
- This is done in the support of hypercalcemia.
- Potassium in the diet will affect the urinary potassium level.
- Drugs which increased the potassium level are diuretics, salicylates, and glucocorticoids.
- Licorice increases the potassium excretion in the urine.
- Potassium is the major cation within the cells (Intracellular).
- Potassium concentration depends upon:
- Kidneys are important for the regulation of the K level.
- Kidneys can not reabsorb the potassium.
- Intake of potassium is balanced by the kidneys by excretion of potassium in the urine.
- Proximal tubules reabsorb all the K.
- Aldosterone additional K excreted into the urine in exchange for Na.
- The distal nephron is the main determinant of urinary K excretion.
- Even if an excess of K taken, still this is excreted in the urine except in patients with renal failure where K level may enter into the toxic level. This is an active process that depends upon ATPase activity.
- This is the amount of potassium excreted in the urine.
- In the case of Alkalosis, there is increased secretion of Potassium in the urine.
- In the case of acidosis, there is decreased secretion of potassium in the urine.
- Urine K+ >30 meq/day is inappropriate in hypokalemic patients and strongly suggest a hyperaldosteronism state.
- Spot urine test K+ > Na+ is also suggesative.
- Urine K+ <30 meq/day reflects renal K+ retention as seen in the diuretic use or gastrointestinal loss.
|6 to 10 years|
|Male||17 to 54|
|Female||8 to 37|
|10 to 14 years|
|Male||22 to 57|
|Female||18 to 58|
|Adult||25 to 125|
- Values vary with diet.
- 25 to 100 meq / L / day (25 to 100 mmol/day).
- Values vary with diet.
Increased urinary Potassium level is seen in:
- Diuretic therapy.
- Cortisone therapy.
- Drugs like penicillin and carbenicillin
- Chronic renal failure.
- Renal tubular acidosis.
- Cushing’s syndrome.
- Excessive intake of licorice.
Decreased urinary Potassium level is seen in:
- I/V glucose infusion.
- Addison disease.
- Acute renal failure where urinary K will be low but the patient will have hyperkalemia.